A vehicle body (e.g., an airplane body, a car body, or a boat body) generally includes an internal skeleton that gives shape to the vehicle, and a skin that overlays the skeleton and provides a smooth outer surface. Modern vehicle bodies are fabricated from a combination of different materials, including composites. For example, the skeleton is typically made of wood, aluminum, or stainless steel, while the skin is typically made of a fiber (e.g., a carbon fiber or fiberglass) embedded within a resin matrix.
Pultrusion is a common way to manufacture straight skeletal parts of a vehicle body (e.g., beams, longerons, etc.). During pultrusion manufacturing, individual fiber strands, braids of strands, and/or woven fabrics are pulled from corresponding spools through a resin bath and through a stationary die. The resin is then allowed to cure and harden. Due to the pulling of the fibers prior to curing, some of the fibers may retain a level of tensile stress after curing is complete. This tensile stress can increase a strength of the skeletal part in the direction in which the fibers were pulled.
A vacuum-assisted resin transfer molding (VARTM) process is commonly used to fabricate the skin of the vehicle body, after the internal skeleton has already been formed. In a VARTM process, sheets of fibrous material are manually pulled over the internal skeleton and then tacked in place. The tacked material is then manually coated with a liquid matrix (e.g., a thermoset resin or a heated thermoplastic), covered with a vacuum bag to facilitate impregnation of the liquid matrix, and allowed to cure and harden.
Although pultrusion manufacturing and VARTM can be an acceptable ways to produce vehicle body parts in some situations, they can also be problematic. In particular, the VARTM-produced skin is often attached to the pultruded skeletal parts and/or reinforced via metallic fasteners (e.g., screws, rivets, and clips). The use of metallic fasteners can drive skeletal design and increase a weight and cost of the vehicle body. In addition, the various vehicle body parts may need to be joined to each other via specially designed hardware, which can also be heavy and costly. Further, electronics (e.g., sensors, heaters, electrical leads, etc.) may need to be added to the vehicle bodies after manufacture, which can further increase the weight, cost, and unreliability. Finally, conventional pultrusion and VARTM manufacturing processes may provide little flexibility in the design and/or use of the vehicle body.
The disclosed composite vehicle body is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.